Two lawsuits accused the late Rev. William J. Cummings, shown in a 1993 photo, of sexually molesting boys

he Archdiocese of Boston knew about a second sexual abuse lawsuit against the late Rev. William J. Cummings two months before deciding last fall that there was no evidence to support another man's accusation that he was molested in the 1980s by both Cummings and Monsignor Michael Smith Foster.

The second lawsuit accused Cummings of molesting a 10-year-old boy at St. Catherine's Church in Somerville in 1982. The church's lawyers acknowledged receiving the lawsuit on Sept. 3 - the same day that Paul R. Edwards of Winchendon abandoned his lawsuit accusing Cummings and Foster of sexual abuse. Foster was cleared on Oct. 30.

Edwards withdrew his lawsuit ''with prejudice,'' meaning he cannot refile it, after questions were raised about the veracity of his charges. Yesterday, however, victim advocates and Edwards's new attorney said that they do not doubt his accusations, and that the existence of another lawsuit against Cummings only reinforces their faith in the credibility of the 35-year-old Edwards.

''I believe Paul's allegation against Father Cummings, without reservation,'' Carmen L. Durso, who is Edwards's lawyer, said in an interview, noting that Edwards told at least two people about the alleged molestation by Cummings more than a decade ago. ''The fact that there is a second allegation against Cummings certainly adds to [Edwards's] credibility.''

Advocates for victims said the existence of the second lawsuit is reason enough for the archdiocese to reopen its investigation of Foster, who is the archdiocese's chief canon lawyer. ''Paul never had any less evidence that he was abused than any other victim,'' said Ann Hagan Webb, the co-coordinator of the New England chapter of the Survivors Network of Those Abused by Priests.

The Rev. Christopher J. Coyne, an archdiocesan spokesman, said he was unaware until the Globe contacted him yesterday that there was a second lawsuit involving Cummings. Church officials, including Coyne, had said several times that the Edwards lawsuit represented the first allegations against either priest.

''The allegations by Paul Edwards against Monsignor Foster should stand or fall on their own, regardless of allegations against another priest, whether they were made by Paul Edwards or anyone else,'' Coyne said. Coyne said the church's investigation into the allegation against Foster determined that the accusation was not credible.

The archdiocese never announced whether it had made the same determination about Cummings.

Coyne confirmed that the church's lawyer, Wilson D. Rogers Jr., was aware of the other lawsuit against Cummings in September. He declined to say, however, whether the Rev. Sean M. Connor, who led the investigation of Edwards's charges, knew that there was more than one allegation against Cummings.

Ellen Martin, an attorney for Foster, said in a statement last night that a thorough church investigation has found the allegations against Foster to be unsubstantiated. ''However packaged, the allegations against Monsignor Foster are false and must end. How much more must Father Mike endure?'' Martin said.

Edwards filed his lawsuit last Aug. 14, accusing Cummings of raping him during an overnight trip to New York City in December 1982, by a youth group from Our Lady Help of Christians Church in Newton. He also charged that Foster sexually molested him numerous times in his rectory bedroom at Sacred Heart Church in Newton between 1980 and 1985.

Cummings died in 1994. Foster was placed on leave in August. But within three weeks, Edwards's attorney resigned as his lawyer and Edwards withdrew his lawsuit after serious questions were raised about the factual claims in his suit. Also, in interviews with the Globe, men and women who had grown up with him cited instances, most of them from their childhood, in which they said Edwards fabricated stories.

After the lawsuit was withdrawn, Foster was reinstated. But a few days later, he was placed back on leave after Edwards met with church investigators and repeated his allegations, although parts of his account of what happened had changed. Six weeks later, the archdiocese determined for a second time that the accusation was unfounded.

But Foster's admission in church documents that became public last month that Edwards had been in his rectory bedroom when he was a teenager sparked calls for the investigation to be reopened. Supporters of Edwards, some of them victims themselves, also questioned the accuracy of allegations about Edwards's personal credibility.

Indeed, accounts by childhood friends challenging Edwards's claim to have been a police officer turned out not to be true. He was a summer policeman on Martha's Vineyard as a youth. Some victim advocates also have complained that questions about whether Edwards is a paraplegic, or how he became paralyzed, are unwarranted.

According to people familiar with the church's investigation, and documents obtained by the Globe, the archdiocese, before exonerating Foster, received substantial information challenging Edwards's credibility from his own parents, other relatives, and longtime family friends.

Webb, who heads the SNAP group and is also a psychologist, said yesterday that she is ''leery'' of many of the challenges to Edwards's personal credibility. ''We have to remember that many survivors of abuse are very troubled. That is often the result of what happened to them, instead of evidence that you cannot believe them,'' she said.

Sidney Gorovitz, the attorney who represents the alleged Somerville victim of Cummings, said his client, who was 10 at the time, was molested inside St. Catherine's Church in Somerville in 1982.

The boy, he said, had sought out Cummings for protection and counsel after he already had been sexually abused by a coach in the Catholic Youth Organization. When he filed the lawsuit against Cummings on June 14, Gorovitz filed a separate lawsuit against the coach, charging that he too abused the boy inside the church.

Both assaults involved sexual abuse, but not rape, Gorovitz said.

Gorovitz said his client had long repressed the memory of both instances of alleged abuse, but had recalled them early last year as the number of other cases of clergy sexual abuse became known. Gorovitz said he is convinced of his client's credibility in recalling the abuse.